in 1917, it unleashed a resumption of unrestricted submarine warfare off the North American coast. Until now, German naval records have not been extensively utilized in English-language histories of this brief but intense period of naval combat in the Atlantic. By studying and comparing both American and German archival sources, author Dominic Etzold has constructed an engaging, modern, and revelatory account of the operation.

By focusing on personalities, Etzold has crafted a work that is enjoyable and engaging to read, not just a reference.